Trail Cutting and Maintenance Guidelines
Spruce-Fir Forest Type
Spruce-fir communities occur at the upper elevations and ridgelines of the Appalachian and Adirondack Mountains. Also known as the Boreal Forest, spruce-fir is dominant in the Adirondacks, far northern New Hampshire and Vermont, Maine, and Quebec.
Not surpisingly, the dominant species are Red Spruce (Picea rubens) and Balsam Fir (Abies balsamea), with sporadic White Spruce (Picea glauca) and Paper Birch (Betula papyrifera). Lesser amounts of Mountain Maple (Acer spicatum) and Mountain Ash (Sorbus americana are also present. The curious difference between spruce and fir is that the cones of fir (Abies) point up, while those of spruce (Picea) hang down.
Spruce-fir forests grow in hostile mountain environments on shallow, rocky soils. Soils erode and slide easily. These mountain forests are also enduring environmental stress from decades of acid rain deposition. The harsh weather, steep slopes, and environmental stress all combine to make high-elevation spruce-fir forests fragile and intolerant of human disturbance.
Even-aged Growth Cycle
Spruce-fir forests are dense and require a lot of cutting to create ski terrain. The most significant feature of this forest type is that spruce-fir stands tend to be even-aged - they grow in groups of all the same age. Therefore spruce-fir stands reach the end of their lifespans (approximately 50 years of age) all at once, and are toppled by weather events, or die standing. Reproduction then starts in the open areas created, and the new trees grow up all at once in dense stands. This occurs in patches on mountainsides and ridges, from 1 acre in size and up. The way in which spruce-fir forests grow and regenerate has significant repercussions upon ski trail development that are often ignored.
Trail and Glade Guidelines
The first issue is with official trails and glades. Because spruce and fir grow up together in dense stands, each individual alone is not able to withstand wind and weather if the surrounding trees are removed. The only way trees can survive out in the open is if they grew up out in the open. Windloading and weather over their lifetimes cause "open-grown" trees grow thicker, stronger stems. Individual spruce and fir that grow in dense stands are willowy and pliable by comparison. Therefore if a trail is cut through spruce-fir, expect subsequent loss of trees along the edges from "windthrow" and "snowloading". The effect of wind can be clearly seen on upper elevation ski trails that are exposed and perpendicular to prevailing winds. The spruce and fir on the exposed (windward) edge will be ragged, broken, and damaged, while those on the protected (leeward) side are dense, green, and healthy.
Gladed trails in spruce-fir forests (such as to the right) are temporary at best for these reasons, and eventually an open treeless trail will result. In glades, the individuals left will eventually fall, exposing the trail to a cycle of increasing wind damage. Glades tend to be cut wider than trails, and so the result can be a very wide trail. The snow retention ability (the "snow fence effect") is less on wide trails versus narrow trails. The root mass of trees felled by wind will be ripped out of the ground exposing rock and accelerating soil erosion.
Cutting official ski trails in spruce-fir forests comes with many potential detrimental impacts upon snow retention, terrain quality, and water quality. Therefore this work must be done with care and thought for the long term. In general several narrow trails are better than one wide one for retention of natural snow. Snowmaking requires wide open trails, and so measures to guard against soil erosion and sliding become most important. Gladed trails in spruce-fir forests are unrealistic.
Management through the Growth Cycle is a Challenge
The second issue is with regard to woods skiing and riding areas, and presents a quandary. Spruce and fir stands become more open as they mature, and can offer great terrain and powder because of their high elevation location. Once these stands start falling down the ski lines become obstructed and hazardous. Dense regeneration starts growing up underneath. One solution is to cut or "buck up" the fallen timber and get it on the ground so it will rot and the lines are again passable. However ski and board edges will mangle the young trees growing underneath. Another option is close these areas to allow the young trees to grow for a number of years unhindered. This requires rope and educational signage as it is taking terrain away from customers.
One bright spot is that because spruce-fir regenerates in dense even-aged groups, it is well-adapted to the technique of establishing "islands" within trails, as discussed under Northern Hardwoods.
If fallen trees are bucked up so skiing can continue, young trees growing up become broken and disfigured, but notably few die. So soil is still held in place, and a dense, uneven tangle of growing trees results. If areas are closed for a number of years and then opened, some young trees will escape damage, while others will not. At some point in time people will ski and ride through an area, and therefore they should be given an easy choice on where to go. Focusing ski/ride impacts through maintenance gives the regeneration in other areas a better chance of outgrowing their physical vunerability to humans descending on snow through their midst.
The second option is to rotate the location of lines, meaning abandoning or closing one line and establishing a replacement line nearby. Opportunities for line rotation are limited by terrain however (the water from a stone rule). Many times a line is located where it is because the terrain offers few other options. Therefore opportunites for line rotation in spruce-fir forests tend to be limited.
In sum, managing spruce-fir woods skiing terrain through its regenerative cycle is a challenge.